Method of rolling composite wire



R. T. HURLEY METHOD OF ROLLING COMPOSITE WIRE Filed March 12, 1927 July 7 1931.

avvuewiioz $51 (l t tom Patented July 7 1931 UNITED STATES ROY T. HURLEY, OF DOBBS FERRY, NEW YORK, ASSIGNOR TO THE B. Gr.

CORPORATION,

A CORPORATION OF NEW YORK METHOD OF ROLL ING COMPOSITE WIRE Application filed March 12, 1927. Serial No. 174,896.

This application relates to the treatment of metal and more-particularly to a method for rolling a compound ingot into a wire havmg a core of uniform diameter and an outer shell of uniform thickness throughout the length of the wire. v

' Such wire when produced may be cut into lengths and used'as electrodes for spark plugs as fully described in my co-pending applica-' tion Ser. No. 625,411, filed March 15, 1923', for spark plugs. When such a wire is used in this manner, it is necessary that the core, which is usually of some heat-conducting metal, be of uniform diameter and the outer shell, which is usually of some heat-resisting metal, be of uniform thickness throughout the length of the electrode, which permits the use of a thin wall of heat-resisting material.

Heretofore the usual procedure followed in rolling an ingot has been to pass the ingot through a series of rolls whereby the shape thereof is varied. In passing through such rolls, the ingot was made to vary its shape by means of the usual circumferential depressions in the rolls to assume the shape of oval, square, round and diamond shape. When such method is applied to a compound ingot; that is, an ingot composed of a shell of one metal and a core of difi'erentmetal, the result' is to shape the ingot into square and diamond shapes, and the wire when eventually produced often has a core of distorted shape resulting in the loss of a uniform diameter thereof and making the use of a thin wall impossible and also in the loss of uniform thickness to the outer shell, and the inner core is apt to break through the outer shell at points.

An object of the present invention is to provide a method of rolling a compound ingot into a wire having a core of uniform diameter and an outer shell of uniform thickness throughout the length of the Wire.

In the present invention, the compound ingot is passed through a series of rolls having circumferential depressions so shaped that the ingot is made to assume alternately oval and round shapes and at the same time the cross sectional area thereof is progressivelydecreased. It has been found in practice that the effect of rblls shaped in'such fashion will preserve the shape of the core in such a manner that after the metal has passed through the last roll the core is found to have a uniform diameter and the outer casing a uniform thickness throughout the length of the wire.

Other objects and advantages of the present invention will become apparent by reference to the accompanying drawings read in the light of the following detailed description wherein Figure 1 1s. a perspectlve vlew of a com' pound ingot to be rolled into awire;

Figure 2 is a View of one arrangement of rolls whereby the ingot is rolled into a Wire; and

Figure 3 is a perspective view of the finished product, that is, a Wire having a core of uniform diameter and anouter shell of uniform thickness.

Referring now to the drawings, 10 indi cates a compound ingot composed of an outer shell 11 of one metal and a core 12 of a different met-a1. The ingot 10 when raised to the proper temperature may be passed through a series of rolls having circumferential depressions in the shape of alternate semi-oval and semi-circular. As illustrated in Fig. 2, one form of rolls may be a pair of rolls 13 and 14 mounted one above the other in such a manner that the peripheries thereof are in approximate contact. Spaced at intervals on the periphery of the rolls 13 and 14 are matched circumferential depressions 15,16, 17, 18, 19, 20, 21 and 22 of alternate shape and of decreasing size. Thus it will be seen that the depressions 15, 17, 19 and 21 are in the shape of a half oval whereby upon passing the ingot between the rolls at these points it is made to assume an oval shape. Likewise the depressions 16, 18, 20 and 22 are in the shape of a half circle whereby the metal upon passing therebetween is made to assume a round shape.

and passed between the rolls at the point of depressions 15. The eifect of the passage at this point is to give to the metal the sha e of an oval in which the outer shell 11 is 0 uniform thickness. The metal in its oval shape may then be passed through the next grooves, i. e., 16, whereby it is made to assume a round shape. This procedure ma be followed out throughout the length of t e rolls until the wire ultimately produced is in the shape illustrated in Fig. 3 wherein the core 12 is shown to have a uniform diameter and the shell 11 a uniform thickness. During this method, the core of the wire is not distorted in any manner by the decreasing siie of depressions, but its size and shape in relation to the outer shell is preserved throughout the process. r

'The apparatus illustrated herein may be varied in any manner desired; that is, the arrangement of rolls may be varied to suit the particular occasion and it is to be understood that the embodiment; illustrated is merely for the purpose of illustration and that the method of rolling an ingot into a wire produced thereby is to be limited only by the scope of the following claim.

I claim:

The method of rolling composite wire which comprises passing a composite ingot having a core of metal softer than that of the outer sheath through a series of rolls shaped to alternately Vary said ingot between oval and round shape and to progressively decrease the cross sectional area thereof.

- In testimony whereof, I have signed my name to this specification.

ROY T. HURLEY. 

